This invention relates to insecticides, and, in particular, to novel formulations for the efficacious delivery of pesticides, water or solvent based insecticides which will not harm the ozone layer of the atmosphere when released.
Halogenated solvents, such as methylene chloride and 1,1,1-trichloroethane are common carriers, diluents and solvents for aerosol sprays. However, they have been restricted due to health and environmental concerns. To alleviate these concerns, many aerosol manufacturers shifted from solvent-based aerosols to water-based aerosols. Many of these aerosols used water as a carrier, dimethylether (DME) as a propellant, and a solvent. The use of DME as a propellant is well known. See for example U.S. Pat. No. 2,358,986 to McGovran et al. Because the insecticide is emulsified in the water, the prior art water-based aerosol insecticides do not have a sustaining good knock-down effect, and when sprayed on a porous surface, such as wood or drywall, the insecticide is significantly absorbed by the surface. As a result, the remaining solvent has a tendency to dilute the insecticide. Thus, consequently, there is not enough insecticide on the surface in sufficient toxic amount to be available for insects to receive in the required amount to effectively kill the same. None of the prior art insecticides disclose a formula wherein the active insecticidal agents are separated from the water or diluent upon release from the aerosol can in order to avoid the problem of dilution, absorbtion and slow knockdown. See for example U.S. Pat. No. 2,358,986 to McGovran et al.; U.S. Pat. No. 4,439,342; U.S. Pat. No. 4,439,343; U.S. Pat. No. 4,439,344; U.S. Pat. No. 4,483,783; and U.S. Pat. No. 4,826,674, all to Albanese; U.S. Pat. No. 4,487,334 to Werding; and, U.S. Pat. No. 4,381,066 and U.S. Pat. No. 4,384,661, both to Page et al.; U.S. Pat. No. 4,187,204 to Howard; U.S. Pat. No. 4,420,575 to Rapaport et al.; U.S. Pat. No. 4,450,253 to Suk; U.S. Pat. No. 3,207,386 to Presant et al.; and, U.S. Pat. No. 4,041,148 and U.S. Pat. No. 4,139,607, both to Simons et al.